Testing the corrosion resistance of aluminum panels is a procedure that involves specific test methods and standards.
The following are a few common methods used to test the corrosion resistance of aluminum panels:
Salt Spray Test (SST):
This is a commonly used accelerated corrosion test that simulates the corrosive conditions found in the natural environment. Aluminum samples are placed in a closed chamber filled with a high concentration of salt spray. After the test, the corrosion resistance of the sample is evaluated by observing the degree of corrosion on the surface.
Cyclic Corrosion Test (Prohesion Test):
Also known as the Alternating Salt Spray Test, the corrosion resistance of aluminum is evaluated by alternating samples of aluminum panels between a salt spray environment and a dry environment, simulating the alternating wet and dry conditions of a natural climate.
Water Jet Test:
In this test, aluminum panels are sprayed with fresh or salt water and then evaluated for corrosion. This method simulates the effects of rain or other fluids on the material.
Electrochemical Testing:
Such as the polarization curve test, the corrosion rate of an aluminum plate can be measured. In this test, the aluminum plate is used as an anode and placed in an electrolyte containing a corrosive medium, and then its electrochemical properties, such as resistivity and current, are measured.
Neutral Salt Spray Test (NSS Test):
This is an internationally recognized method of evaluating corrosion resistance for automotive coatings. In this test, the samples are exposed to a closed environment containing a certain concentration of neutral salt solution.
Natural Exposure Test:
Aluminum panels are hung in a specific corrosive environment and exposed for a period of time to observe their corrosion condition. This method is time-consuming, but it provides data on long-term corrosion behavior in a specific environment.
ASTM Standard Tests:
ASTM B117, for example, provides specific methods for salt spray testing, while ASTM G85 covers accelerated corrosion test methods, including salt spray, cyclic salt spray, moisture, water spray, and high temperature and high humidity environment testing.
Microanalysis:
Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and transmission electron microscopy (TEM) are used to observe the microstructure and corrosion products of aluminum panels.
Mass Loss Test:
The extent of corrosion of a material is assessed by measuring the difference in mass of the material before and after corrosion.
Before conducting these tests, it is important to select a test method that is compatible with the environment and intended use of the aluminum plate, and to refer to the appropriate industry standards, such as ISO, ASTM or DIN. This will ensure the accuracy and reliability of the test results.
